Cubic bag packages which simulate a carton have become quite popular for packaging disposable infant diapers and adult briefs. These bags make it possible to create the "carton" look with a similar degree of packaging line automation, but with a much reduced material cost. The bag offers nearly one hundred percent surface availability for graphics, a perfectly contoured fit, and additional features such as add-on carrying handles. Also, the filled bags are readily stackable. A good background description of these bags appears in the article entitled "Poly Bag Packaging For Disposable And NonWoven Products," by A. G. Thatcher, published Mar. 15, 1977, in Montreal, Canada. Reprints of this article are available from Technomic Publishing Co., Inc. of Westport, Connecticut.
A popular form of "cubic" bag, equipped with a "loop" type carrying handle, is disclosed by German Patent Publication No. 2,155,091, published May 10, 1972. This same bag and handle are disclosed in U.S. Pat. No. 3,370,630, granted Feb. 27, 1968, except that the bag is not shown in a full packed condition and the top of the bag is not accurately drawn. French Patent Publication No. 2,053,590, published on Apr. 16, 1971, also relates to a cubic bag and discloses three styles of carrying handles, each of which has opposite side portions which are heat sealed to the bag where the gusset meets the front and rear walls of the bag.
It is known to heat seal a handle web to a bag web and then cut the handle web to form the desired handle shape. German Patent Publication No. 2,157,072, published June 7, 1973, discloses the use of this method in the manufacture of a flat bag. U.S. Pat. No. 4,573,203, granted Feb. 25, 1986, to Harry R. Peppiatt, discloses the use of this method for providing a loop handle at the gusset end of a cubic bag.
U.S. Pat. No. 4,539,705, granted Sept. 3, 1985, to Patrick A. Baines discloses a cubic bag having a strap-like handle which extends lengthwise of the gusset. The ends of the handle are connected to the endwalls of the filled bag. This patent sets forth a very comprehensive description of the various types of cubic bags which have been used for packaging disposable diapers and similar products.
U.S. Pat. No. 3,240,420, granted Mar. 15, 1966, to John N. Membrino, and Canadian Pat. No. 907,574, granted Aug. 15, 1972, to Herbert F. Gurband disclose bags which are manufactured to include both a gusset and handle portions at an upper end of the bag. This particular construction is undesirable because it requires the use of an extremely wide web of plastic material. Also, the elongated grip hand holes which are illustrated create stress concentrations and undesirable and unsightly wrinkling of the bag material.
U.S. Pat. No. 3,567,110 granted Mar. 2, 1971, to Rinnosuke Susuki, discloses a bottom-loaded plastic bag which has a closed top and a pair of grip handles on the opposite side of the bag. The grip handles of this bag are constructed from a relatively thick plastic. This permits the use of elongated hand receiving openings without undesirable wrinkling or stress concentrations. The thick handles function as beams and thus it is the stiffness of the handle material which provides good weight distribution between the bag and handles.
The principal object of the present invention is to provide a bottom-loaded cubic bag, for use to package disposable diapers and similar products, having flexible ear handles on the opposite sides of the bag, with a configuration which provides good stress distribution between bag and handle and a pleasing appearance both when the handles are stowed and when they are in use.